Abstract A process for preparing polyethylene terephthalate wherein dimethyl terephthalate is reacted with ethylene glycol to form an ester of ethylene glycol and terephthalic acid or where terephthalic acid is reacted with ethylene glycol to form an ester of terephthalic acid and ethylene glycol where the resulting ester is polycondensed in the presence of a polycondensation catalyst, the improvement comprising carrying out the condensation or polymerization of the ester in the presence of a catalytic amount of a trivalent antimony compound exhibiting two direct carbon to antimony bonds and one direct bond from an antimony atom to oxygen; to oxygen linking an organic radical to said antimony atom; to oxygen linking another antimony atom to said antimony atom; or to a halogen atom.
The process of claim 1 wherein said antimony compound is of the formula R2Sb(OOCR'') wherein R and R'' are hydrocarbons.
Claim 2
Dependent Claim
12 words
The process of claim 1 wherein said antimony compound is diarylantimony carboxylate.
Claim 3
Dependent Claim
12 words
The process of claim 3 wherein said antimony compound is diphenylantimony acetate.
Claim 4
Dependent Claim
12 words
The process of claim 3 wherein said antimony compound is diphenylantimony p-chlorobenzoate.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein said antimony compound is diphenylantimony 2-ethylhexanoate.
Claim 6
Dependent Claim
31 words
The process of claim 1 wherein said antimony compound is of the formula R2SbX wherein R is a hydrocarbon and X is selected from the group consisting of oxygen and halogen.
Claim 7
Dependent Claim
12 words
The process of claim 7 wherein said antimony compound is diarylantimony chloride.
Claim 8
Dependent Claim
12 words
The process of claim 7 wherein said antimony compound is diphenylantimony chloride.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein said antimony compound is dialkylantimony oxide.
Claim 10
Dependent Claim
12 words
The process of claim 7 wherein said antimony compound is diarylantimony oxide.
Claim 11
Dependent Claim
12 words
The process of claim 7 wherein said antimony compound is diphenylantimony oxide.
Claim 12
Dependent Claim
19 words
The process of claim 1 wherein said antimony compound is of the formula (R2Sb)2O wherein R is a hydrocarbon.
Claim 13
Dependent Claim
12 words
The process of claim 13 wherein said antimony compound is bis(dialkylantimony) oxide.
Claim 14
Dependent Claim
12 words
The process of claim 13 wherein said antimony compound is bis(diarylantimony) oxide.
Claim 15
Dependent Claim
12 words
The process of claim 13 wherein said antimony compound is bis(diphenylantimony) oxide.